It is not 30 years old. It's still 12 yo Dalmore years in bottle don't count towards age of spirit hence whisky is matured in oak barrels. That time is rly the time that matters the most. It will definitely be worth more than shelf version. If you don't live in UK or some major city it might be hard to even sell this. Visit your local auction house and check what they know about it. Don't expect thousands of dollars unless you think you are very lucky. You can expect couple hundred tho if you find buyer that is.